1. Field of the Invention
The disclosures herein generally relate to an image forming apparatus, and in particular relate to an image forming apparatus provided with, in addition to a paper feeding unit for a recording medium (e.g. a roll paper), a manual paper feeding unit for another kind of recording medium (e.g. a cut paper).
2. Description of the Related Art
Conventionally, image forming apparatuses, each provided with a conveyance path and a paper feeding roller only for a cut paper, which is manually fed, separately from a paper feeding unit for a roll paper, have already been known. Moreover, image forming apparatuses, each manually feeding a paper by making a cut paper butt directly against a nip of a conveyance roller common to the printing on a roll paper, are also known. Moreover, a method of releasing a nip of a conveyance roller from a side of a paper discharge port upon printing on a roll paper, inserting manually a cut paper to a back end of paper (a leading end upon inserting), and nipping again with the conveyance roller is also known.
However, a paper which is manually fed is not necessarily a new paper, and has a wrinkle or a bend in the leading end in some cases. Moreover, there is a case of cutting a roll paper to use (a cut paper), or a case of printing on a backing paper of a cut paper. In the above-described cases, there is a problem that upon transporting a paper through a nip portion of the conveyance roller by the conventional automatic paper feeding, an edge fold occurs in a leading end of paper, or a skew or a jam occurs.
Moreover, a height of a scanner-integrated image forming apparatus which can be provided with plural roll papers is restricted due to operability of a scanner unit. Moreover, there is also demand for feeding a thick paper manually. However, in an image forming apparatus, of which front access is required, it is difficult to arrange a tray only for manual paper feeding on a machine front side. This is because a thick paper may become creased upon being turned.
Moreover, in the method of releasing a nip of a conveyance roller from a side of a paper discharge port, inserting manually a cut paper to a back end of paper (a leading end upon inserting), and nipping again, in a case of a long paper, it is troublesome to pass the paper into a conveyance path manually. Furthermore, there is a problem that depending on a curling direction of a paper, the paper may enter a conveyance path for a roll paper, and since an alignment of paper is performed by sight, a skew may occur.
Japanese Published Patent Application No. H5-85647 discloses inserting a manual feeding sheet between a conveyance guide and a manual feeding roller so that a failure of sheet feeding will not occur. However, since it is necessary to press the manual feeding roller by a cut paper upon inserting, a leading end of sheet could be held in a state of being deflected, creased or wrinkled. Moreover, in a case of a sheet of low stiffness, it may not be inserted properly and may be jammed.